Stability of individual loudness functions obtained by magnitude estimation and magnitude production

Abstract

A correlational analysis of individual magnitude estimation and production exponents at the same frequency has been performed as well as an analysis of individual exponents produced across frequency (250, 1000, and 3000 Hz). Results show, in agreement with those of Wanschura and Dawson [J. Exp. Psychol. 102, 806-812 (1974)], that a moderately positive but not significant correlation coefficient is obtained between individual magnitude estimation and production data. However, strong positive correlation coefficients are found when individual magnitude estimation and production data are combined and then, compared across frequency. These results imply that individual differences in exponents not only persist over time but also remain stable across changes in stimulus frequency. Further results disclose that the slope (exponent) of the equal-sensation function between two different stimuli can be predicted from individual magnitude estimation and production data. Examples are given showing that the stability of individual exponents can be used to predict the slope of the loudness-recruitment function produced by ears with cochlear pathology, i.e., transitivity can be achieved for individuals.